#include <vector>
#include <queue>
#include <stack>
#include <list>
#include <set>
#include <algorithm>
#include <utility>
#include <string>
#include <functional>
#include <sstream>
#include <fstream>
#include <iostream>
using namespace std;
#define FOR(i,a,b) for (i=a;i<=b;i++)
#define fori(it,v) for (it=(v).begin();it!=(v).end();it++)
#define pb push_back
#define mp make_pair
#define fs first
#define ss second
#define all(c) c.begin(),c.end()
#define pf push_front
#define popb pop_back
#define popf pop_front
int v[1005],vs[1005],vd[1005],cap[1005][1005],pred[1005],n;
vector<vector<int> >a(1005);
int flux()
{
	queue<int> q;
	memset(v,0,sizeof(v));
	pred[n]=0;
	q.push(1);
	v[1]=1;
	while (!q.empty())
	{
		int nod=q.front();
		q.pop();
		vector<int>::iterator it;
		fori(it,a[nod])
		{
			if (!v[*it]&&cap[nod][*it])
			{
				pred[*it]=nod;
				v[*it]=1;
				q.push(*it);
			}
		}
	}
	if (pred[n]==0)
		return 0;
	int y=n,capacitate=1<<30;
	while (pred[y])
	{
		capacitate=min(capacitate,cap[pred[y]][y]);
		y=pred[y];		
	}
	y=n;
	while (pred[y])
	{
		cap[pred[y]][y]-=capacitate;
		cap[y][pred[y]]+=capacitate;
		y=pred[y];
	}
	return 1;
}
void bfss()
{
	queue<int> q;
	q.push(1);
	vs[1]=1;
	while (!q.empty())
	{
		int nod=q.front();
		q.pop();
		vector<int>::iterator it;
		fori(it,a[nod])
			if (!vs[*it]&&cap[nod][*it])
			{
				q.push(*it);
				vs[*it]=1;
			}
	}		
}
void bfsd()
{
	queue<int> q;
	q.push(n);
	vd[n]=1;
	while (!q.empty())
	{
		int nod=q.front();
		q.pop();
		vector<int>::iterator it;
		fori(it,a[nod])
			if (!vd[*it]&&cap[*it][nod])
			{
				q.push(*it);
				vd[*it]=1;
			}
	}
}
int main()
{
	FILE *in,*out;
	int m,i,x,y,z;
	vector<pair<int,int> > b;
	vector<int> c;
	in=fopen("critice.in","r");
	out=fopen("critice.out","w");
	fscanf(in,"%d%d",&n,&m);
	FOR(i,1,m)
	{
		fscanf(in,"%d%d%d",&x,&y,&z);
		b.pb(mp(x,y));
		a[x].pb(y);
		a[y].pb(x);
		cap[x][y]=cap[y][x]=z;
	}
	while (flux());
	bfss();
	bfsd();
	FOR(i,0,m-1)
	{
		if ((vs[b[i].fs]&&vd[b[i].ss]&&cap[b[i].fs][b[i].ss]==0)||(vs[b[i].ss]&&vd[b[i].fs]&&cap[b[i].ss][b[i].fs]==0))
		{
			c.pb(i+1);
		}
	}
	fprintf(out,"%d\n",c.size());
	vector<int>::iterator it;
	fori(it,c)
		fprintf(out,"%d\n",*it);
	fclose(in);
	fclose(out);
	return 0;
}